JP2005187800A - Resin composition, and prepreg, metal-clad laminated sheet, and printed-wiring board using the composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition excellent in both characteristics of electrical characteristics represented by a relative dielectric constant and dielectric loss tangent, and flame retardant characteristics, using a nitrogen-containing phenolic resin represented by a melamine-modified novolak, and to provide a prepreg, a metal-clad laminated sheet, and a printed-wiring board using the composition. <P>SOLUTION: The resin composition comprises (A) a non-halogenated epoxy compound having a novolak structure, (B) a melamine-modified phenolic resin curing agent in which a hydroxy group equivalent is 145-190 g/eq and a content of the nitrogen amount is 14.0-25.0 wt.%, as essential components, a ratio of mole numbers (c) of epoxy groups in the whole resins and mole numbers of the phenolic hydroxy groups (d), (d)/(c) being 0.4-0.7, and a ratio of the resins having the novolak structure to the sum total of the epoxy resins and the phenolic resins being ≥70 wt.%. The prepreg, the metal-clad laminated sheet, and the printed-wiring board using the composition are provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a resin composition excellent in both electric characteristics represented by relative permittivity and dielectric loss tangent and flame retardancy, a prepreg using the resin composition, a metal-clad laminate, and a printed wiring board.

  Epoxy resins have excellent mechanical strength, heat resistance, adhesion, and electrical insulation, so they are used in many industrial fields such as paint, electricity, civil engineering, and adhesion, and many epoxy resins are also used in printed wiring boards. Yes. Electrical equipment using these printed wiring boards is usually imparted with flame retardancy to ensure safety against fire. Conventionally, brominated flame retardants such as TBBA (tetrabromobisphenol A) are often used to impart flame retardancy. However, it is said that harmful dioxins are generated due to the combustion of brominated flame retardants at the time of incineration of printed wiring boards, and regulations are expected to be imposed in the future. For these reasons, many flame retardants containing phosphorus and nitrogen have been studied as flame retardants to replace brominated flame retardants, and melamine-modified novolak and the like are often used as phenol resins containing nitrogen components. .

Japanese Patent Laid-Open No. 11-43536 JP 2002-161191 A

  However, it has been found that a phenol resin containing a nitrogen component deteriorates dielectric properties due to the influence of a hydroxyl group. The present invention uses a nitrogen-containing phenolic resin typified by a melamine-modified novolak, a resin composition excellent in both properties of a dielectric constant, a dielectric loss tangent, an electrical property and a flame retardant property, and the resin composition. It aims at providing the used prepreg, a metal-clad laminated board, and a printed wiring board.

  In order to solve the above problems, the present invention is characterized by the following items (1) to (5).

  (1) (A) a non-halogenated epoxy compound having a novolak structure, and (B) a melamine-modified phenol resin cured with a hydroxyl group equivalent of 145 to 190 g / eq and a nitrogen content of 14.0 wt% to 25.0 wt% An agent as an essential component, the ratio (d) / (c) of the number of moles of epoxy groups (c) and the number of moles of phenolic hydroxyl groups (d) in the total resin is 0.4 to 0.7, and A resin composition comprising 70 wt% or more of a resin having a novolac structure based on a total amount of an epoxy resin and a phenol resin.

  (2) A prepreg obtained by impregnating a base material with the resin composition described in (1) above.

  (3) The prepreg as described in (2) above, wherein the substrate is a glass woven fabric.

  (4) A metal-clad laminate comprising a metal layer formed on both sides or one side of the prepreg or laminate thereof described in (2) or (3) above.

  (5) A printed wiring board obtained by applying circuit processing to the metal-clad laminate according to (4).

  Since the resin composition in the present invention is excellent in both electrical characteristics and flame retardancy, it can improve electrical characteristics and flame retardancy in prepregs, metal-clad laminates and printed wiring boards produced using the resin composition. Is possible.

  The resin composition of the present invention contains (A) a non-halogenated epoxy compound having a novolak structure and (B) a melamine-modified phenol resin curing agent as essential components.

  Examples of the non-halogenated epoxy compound having the (A) novolak structure include phenol novolac epoxy resins, cresol novolac epoxy resins, phenol biphenylene novolac epoxy resins, bisphenol A novolac epoxy resins, and the like. It is not limited to these, and several types may be used simultaneously. Considering heat resistance and high glass transition temperature, it is desirable to use novolac type epoxy resins such as phenol novolac epoxy resin, bisphenol A novolac epoxy resin, cresol novolac epoxy resin, etc., and considering dielectric properties, phenol biphenylene novolac type epoxy resin It is desirable to use an epoxy resin such as In addition, non-halogenated epoxy having other structures may be used in combination, and examples thereof include bifunctional epoxy resins such as bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and biphenyl epoxy resin. It is not limited to these, and several types may be used simultaneously.

  Examples of the (B) melamine-modified phenol resin curing agent include melamine-modified novolak resin, benzoguanamine-modified novolak resin, and acetoguanamine-modified novolak resin. Moreover, it is preferable that the hydroxyl equivalent of (B) component is 145-190 g / eq. When the hydroxyl equivalent of component (B) is less than 145 g / eq, the ratio (d) / (c) of the number of moles of epoxy groups (c) and the number of moles of phenolic hydroxyl groups (d) in the total resin is 0.4. When adjusted to the range of ˜0.7, the blending amount of the component (B) decreases, so the nitrogen content decreases with respect to the total solid content of the resin composition of the present invention, and the flame retardancy improvement effect is small. . Moreover, when the hydroxyl equivalent of (B) component exceeds 190, when (d) / (c) is matched with the range of 0.4-0.7, the compounding quantity of (B) component increases, epoxy is This is not preferable because it deteriorates the inherent properties. Moreover, it is preferable that the nitrogen content of (B) component is 14.0 wt%-25.0 wt% when the flame retardance characteristic of the resin composition, the reactivity, and the mechanical characteristic as a hardened | cured material are considered.

  In the present invention, the ratio of the number of moles of epoxy groups (c) to the number of moles of phenolic hydroxyl groups (d) in the total resin (component (A), component (B), and other resins) (d) / (C) is preferably in the range of 0.4 to 0.7, and when (d) / (c) is less than 0.4, varnish reactivity, mechanical properties as a resin cured product (bending and tension) In addition, the adhesive strength tends to decrease, and the inherent properties of the epoxy resin may be impaired. On the other hand, when (d) / (c) exceeds 0.7, the glass transition temperature (Tg) and the heat resistance tend to decrease.

  The (A) non-halogenated epoxy compound having a novolak structure and (B) the melamine-modified phenol resin curing agent are all solids containing all resins and flame retardants and inorganic fillers used as necessary. Among them, it is preferably contained at 50 wt% or more, and more preferably 55 to 65 wt%.

  Moreover, you may use a hardening accelerator as needed in order to accelerate | stimulate hardening of resin. The type of the accelerator is not particularly limited. For example, an imidazole compound, an organic phosphorus compound, a secondary amine, a tertiary amine, a quaternary ammonium salt, or the like is used, and two or more types are used in combination. Also good. Examples of the imidazole compound include imidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 4 5-diphenylimidazole, 2-methylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline, 2-heptadecylimidazoline, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-phenyl-4-methylimidazole, 2 -Ethylimidazoline, 2-isopropylimidazoline, 2,4-dimethylimidazoline, 2-phenyl-4-methylimidazoline and the like. These may be masked with a masking agent. Examples of the masking agent include acrylonitrile, phenylene diisocyanate, toluidine isocyanate, naphthalene diisocyanate, methylene bisphenyl isocyanate, and melamine acrylate. Although the compounding quantity of a hardening accelerator is not specifically limited, It is preferable that it is 0.01-10.0 weight part with respect to 100 weight part of all resins.

  In addition, the resin composition of the present invention improves water absorption characteristics and heat resistance by containing 70 wt% or more of a resin having a novolac structure with respect to the total amount of epoxy resin and phenol resin in the composition. This is preferable. When the blending amount is less than 70 wt%, the crosslink density is lowered even as a cured product and the water absorption rate is increased, so that the dielectric characteristics at the time of water absorption are deteriorated, which is not preferable. The cured product preferably has a water absorption rate of 0.5 wt% or less after PCT 1.5 hr treatment.

  The resin composition of the present invention as described above is preferably used after being diluted with a solvent and varnished. The kind of solvent used at this time is not particularly limited. For example, alcohol solvents such as methanol and ethanol, ether solvents such as ethylene glycol monomethyl ether, ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, N, There are amide solvents such as N-dimethylformamide, aromatic hydrocarbon solvents such as toluene and xylene, ester solvents such as ethyl acetate, and nitrile solvents such as butyronitrile. Also good. Moreover, there is no restriction | limiting in particular as solid content concentration in a varnish, Although it can change suitably with the kind of resin composition, an inorganic filler, those compounding quantities, etc., it is preferable that it is the range of 50 weight%-80 weight%. . If it is less than 50% by weight, the varnish viscosity tends to be low and the resin content of the prepreg tends to be low, and if it exceeds 80% by weight, the appearance of the prepreg tends to be remarkably reduced due to the thickening of the varnish. More preferably, it is 50 weight%-70 weight%.

  The prepreg of the present invention can be produced by impregnating a base material with the varnish of the resin composition of the present invention and drying it.

  The base material used for the prepreg of the present invention is not particularly limited as long as it is generally used when producing a metal foil-clad laminate or a multilayer printed wiring board. The fiber substrate can be used. Examples of the fiber base material include glass, alumina, asbestos, boron, silica alumina glass, silica glass, tyrano, silicon carbide, silicon nitride, zirconia, and other inorganic fibers, aramid, polyetheretherketone, polyetherimide, polyether There are organic fibers such as sulfone, carbon, cellulose and the like, and mixed papers thereof. Among these, woven fabrics of glass fibers are particularly preferably used. As the base material used for the prepreg, a glass cloth of 20 μm to 200 μm is particularly preferably used.

  Moreover, it is preferable that the amount of impregnation of a varnish shall be 35-70 weight% of varnish solid content with respect to the total amount of a varnish solid content and a base material.

  Moreover, it is preferable that the temperature at the time of prepreg drying is 80 to 200 degreeC, and what is necessary is just to determine a drying time suitably by the balance with the gelling time of a varnish. The dried prepreg preferably has 80% by weight or more of the solvent used in the varnish volatilized.

  In the metal-clad laminate of the present invention, for example, a metal foil is laminated on one or both sides of the prepreg of the present invention or a laminate in which a plurality of the prepregs are laminated, and this is usually 130 to 250 ° C, preferably 150 to 200 ° C. Can be produced by heating and pressing at a temperature in the range of usually 0.5 to 20 MPa, preferably 1 to 8 MPa. By using a metal foil to form a metal-clad laminate, circuit processing can be applied to this to obtain a printed circuit board.

  As the metal foil, a copper foil or an aluminum foil having a thickness of 5 to 200 μm is usually used. Besides, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin A composite foil with a three-layer structure in which an alloy or the like is used as an intermediate layer and a copper layer of 0.5 to 15 μm and a copper layer of 10 to 300 μm are provided on both sides, or a two-layer structure composite foil in which aluminum and copper foil are combined It can also be used and is not particularly limited.

  The printed wiring board of the present invention can be produced by subjecting the metal foil surface or the metal foil etched surface of the metal-clad laminate of the present invention to circuit processing by a conventional method. Furthermore, the printed wiring board with the circuit formed on both sides or one side is used as the inner layer board, prepreg is arranged on both sides or one side, after press molding, drilling with a drill etc. for interlayer connection, plating etc. is performed, circuit processing It can be set as a multilayer printed wiring board by giving etc.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples without departing from the technical idea of the present invention.

(Example 1)
In a glass flask equipped with a stirrer, a condenser and a thermometer, 100 parts by weight of a cresol novolac type epoxy resin (epoxy equivalent: 210, manufactured by Japan Epoxy Resin Co., Ltd., E180), a cresol skeleton-containing melamine-modified phenol resin [hydroxyl equivalent: 184 , 24.0% nitrogen content, 50% solvent (methyl ethyl ketone, propylene glycol monomethyl ether) content, Dainippon Ink & Chemicals, Phenolite EXB9831] 70 parts by weight dissolved with methyl ethyl ketone and diluted to a solid content of 60 It adjusted with MEK so that it might become a resin composition varnish of a weight% [(d) / (c) = 0.4]. The varnish was impregnated into a glass cloth (style 2116, E glass) having a thickness of about 100 μm and dried at 150 ° C. for 5 minutes to obtain a prepreg having a resin content of 50% by weight. Six prepregs were stacked, 18 μm copper foils were stacked on both sides, and heated and pressed under a pressing condition of 180 ° C. for 60 minutes and 4.0 MPa to prepare a copper-clad laminate. This copper clad laminate had a relative dielectric constant of 3.79 and a dielectric loss tangent of 0.0086. The relative dielectric constant and dielectric loss tangent are values obtained by measuring the dielectric constant and dielectric loss tangent at 1 GHz with an impedance material analyzer HP4291B manufactured by Hewlett-Packard Co., Ltd. after etching the copper foil of the test sample.

(Example 2)
As resin components, cresol novolac type epoxy resin (epoxy equivalent: 210, manufactured by Japan Epoxy Resin Co., Ltd., E180) 54 parts by weight, biphenyl type epoxy resin (epoxy equivalent: 186, Japan Epoxy Resin, YX4000) 46 parts by weight, cresol skeleton Contains 106 parts by weight of melamine-modified phenolic resin [hydroxyl equivalent: 151, nitrogen content: 18.0%, solvent (methyl ethyl ketone, propylene glycol monomethyl ether) 50%, Dainippon Ink & Chemicals, Phenolite EXB 9848] A resin composition varnish was prepared in the same manner as in Example 1 except that the copper-clad laminate was prepared [(d) / (c) = 0.7]. This copper clad laminate had a relative dielectric constant of 3.79 and a dielectric loss tangent of 0.0086.

(Example 3)
As resin components, phenol novolac epoxy resin (epoxy equivalent: 190, manufactured by Dainippon Ink Co., Ltd., N-770) 100 parts by weight, melamine modified phenolic resin [hydroxyl equivalent: 146, nitrogen content: 19.0%, Dainippon Ink Chemical Industry Co., Ltd., 40% solvent (methyl ethyl ketone), phenolite LA1356] 70 parts by weight, except that 43 parts by weight of triphenyl phosphate as a flame retardant was dissolved together with N, N-dimethylformamide to prepare a resin composition varnish A copper clad laminate was obtained in the same manner as in Example 1 [(d) / (c) = 0.55]. The copper clad laminate produced at this time had a relative dielectric constant of 3.95 and a dielectric loss tangent of 0.0112.

(Comparative Example 1)
As resin components, cresol novolac type epoxy resin (epoxy equivalent: 210, manufactured by Japan Epoxy Resin Co., Ltd., E180) 100 parts by weight, melamine-modified phenol resin [hydroxyl equivalent: 146, nitrogen content: 19.0%, solvent (methyl ethyl ketone) Resin composition varnish was prepared in the same manner as in Example 1 except for using 40%, Dainippon Ink and Chemicals, Phenolite LA1356] 116 parts by weight, and a copper-clad laminate was prepared [(d ) / (C) = 1.0]. This copper clad laminate had a relative dielectric constant of 3.88 and a dielectric loss tangent of 0.0102.

(Comparative Example 2)
As resin components, cresol novolac type epoxy resin (epoxy equivalent: 210, manufactured by Japan Epoxy Resin Co., Ltd., E180) 50 parts by weight, biphenyl type epoxy resin (epoxy equivalent: 186, Japan Epoxy Resin, YX4000) 50 parts by weight, melamine modified Example 1 except that 86 parts by weight of phenol resin [hydroxyl equivalent: 146, nitrogen content: 19.0%, solvent (methyl ethyl ketone) 40%, Dainippon Ink & Chemicals, Phenolite LA1356] was used. Similarly, a resin composition varnish was prepared to produce a copper clad laminate [(d) / (c) = 0.7]. This copper clad laminate had a relative dielectric constant of 3.81 and a dielectric loss tangent of 0.0090.

(Comparative Example 3)
As resin components, cresol novolac type epoxy resin (epoxy equivalent: 210, manufactured by Japan Epoxy Resin Co., Ltd., E180) 100 parts by weight, melamine-modified phenol resin [hydroxyl equivalent: 127, nitrogen content: 13.0%, solvent (methyl ethyl ketone) Resin composition varnish was prepared in the same manner as in Example 1 except that 30% by weight of 40% contained, Dainippon Ink and Chemicals, Phenolite LA7054] was used, and a copper-clad laminate was prepared [(d) /(C)=0.3]. This copper clad laminate had a relative dielectric constant of 3.82 and a dielectric loss tangent of 0.0091.

(Comparative Example 4)
As a resin component, phenol novolac epoxy resin (epoxy equivalent: 190, manufactured by Dainippon Ink Co., Ltd., N-770) 100 parts by weight, melamine-modified phenol resin [hydroxyl equivalent: 125, nitrogen content 12.0%, solvent (methyl ethyl ketone) 40%, Dainippon Ink and Chemicals, Phenolite LA7054] 110 parts by weight, 43 parts by weight of triphenyl phosphate as a flame retardant were dissolved together with N, N-dimethylformamide to prepare a resin composition varnish (patent) A copper-clad laminate was obtained in the same manner as in Example 1 except for the composition described in Example 1 of Document 1 [(d) / (c) = 1.0]. The copper-clad laminate had a relative dielectric constant of 4.11 and a dielectric loss tangent of 0.0138. Also, the flammability (burning time) and water absorption characteristics of the copper-clad laminates of Examples and Comparative Examples produced above. Was measured according to the following measurement method.

(Burning time)
A copper foil on the entire surface of the base material was etched, and the test conditions were performed according to UL-94.

(Water absorption characteristics)
The entire surface of the copper foil on the surface of the base material is etched, cut to 50 mm × 50 mm with a diamond cutter (wet plate cutter), dried at 105 ° C. for 1 hour, and the sample weight is measured. Thereafter, the sample was treated with PCT (pressure cooker test) for 1.5 hours, water droplets on the sample surface were wiped off, the sample weight was measured again, and the water absorption was calculated from the weight difference before and after the treatment.

  Table 1 shows the results of the various evaluation tests described above.

表１より、実施例の銅張積層板は比較例の銅張積層板に対し、比誘電率、誘電正接に代表される電気特性に優れ、また、難燃特性にも優れていることがわかる。

From Table 1, it can be seen that the copper-clad laminates of the examples are superior to the copper-clad laminates of the comparative examples in electrical characteristics typified by relative dielectric constant and dielectric loss tangent, and also in flame retardant characteristics. .

Claims (5)

  (A) A non-halogenated epoxy compound having a novolak structure, and (B) a melamine-modified phenol resin curing agent having a hydroxyl group equivalent of 145 to 190 g / eq and a nitrogen content of 14.0 wt% to 25.0 wt% are essential. The ratio (d) / (c) of the number of moles of epoxy groups (c) and the number of moles of phenolic hydroxyl groups (d) in the total resin is 0.4 to 0.7, and A resin composition comprising 70 wt% or more of a resin having a novolac structure with respect to the total amount of phenol resin.   A prepreg comprising the base material impregnated with the resin composition according to claim 1.   The prepreg according to claim 2, wherein the substrate is a glass woven fabric.   A metal-clad laminate comprising a metal layer formed on both sides or one side of the prepreg or laminate thereof according to claim 2 or 3. A printed wiring board obtained by applying circuit processing to the metal-clad laminate according to claim 4.